There might be an equation somewhere that you can use to calculate the distance between two points

Not quite sure where to start with this one.

1. 1.0 strictly equals 1 in JS. That is not a reason this test could be failing.
2. All numeric literals in JS are instances of Number. There in fact cannot be a difference between a floating-point representation of integers and "actual" integers without using BigInt - they are the same thing.
3. What is printed is generally irrelevant to passing tests on Codewars.
4. You can see there are over 1000 successful JS submissions, so it is clearly not true that the last test case will never be achieved.

console.log(1 === 1.0);
>> true

Not a kata issue, closing - and please double-check your issues before you raise them :)

Thank you so much for your explanation and the function explaining it. I tested it and it worked with my assumptions in the way your functions explained. I shall look more into bitwise operations as well.

English can be weird. "Every other" and "all others" mean entirely different things.

No, "every other" number means in English that you remove 2, keep 3, remove 4, keep 5, &c.

So alternate keeping and removing, in alternating directions.

Hi. Please use spoiler flag next time. And please read this:

• https://docs.codewars.com/training/troubleshooting/
• https://docs.codewars.com/references/markdown/#code-block

OP solved it closing ~~

Understanding the kata is the kata ;)

I figured it out.
Looking at the other solution makes me want to kill myself. :-D
I always hated the stock markets, and now I know why.

That is part of the kata to figure that out. Make sure you maximise profit.

Then the same question remains: how to tell when you're buying or selling?

it's not fixed on the number of the day

[ 1, 2, 3, 4, 5, 6]   => 15  (buy at 1,2,3,4,5 and then sell all at 6)

If you buy at the first 5 days, you'll pay 1+2+3+4+5 = 15 and have 5 stocks. The 6th day you sell 5 stocks for 6 per stock, rendering 30 revenue. 30 - 15 = 15.
Any other combination of choices you make will not give you 15 or more profit.